Cutter-head.



c. '1). MARSH, DEG'D.

I 1' STRYKEB ADMINISTRATOR CUTTER HEAD.

APPLICATION FILED MAB-.31, 1910.

Patented Mar. 26, 1912.

2 SHBBT8SEBET 1.

Mam'h,

, 35 lggum G. D. MARSH, DEGD. r. r. BTRYKER, ADMINISTRATOR.

CUTTER HEAD.

APPLICATION FILED mn.s1, 1910.

7 1,02 1,202. Patented Mar. 26, 1912.

F I j 2 BEEETB-SHEET 2.

III/IIII/A UNITED STATES PATENT OFFICE.

CALVIN D. MARSH, OF WILLIAMSPORT,PENNSYLVANIA; FRANK F. STRYKER, ADMIN-ISTRATOR 0F SAID MARSH, DECEASED, ASSIGNOR T0 HERMANCE MACHINE 00., 0FWILLIAMSPORT, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

CUTTER-HEAD.

Specification of Letters Patent.

Patented Mar. 26, 1912.

To all whom it may concern Be it known that I, CALVIN D. MARSH, acitizen of the United States, residing at Williamsport, in the county ofLycoming and State of Pennsylvania, have invented a new and usefulCutter-Head, of which the following is a specification.

The invention relates to improvements in cutter heads.

The object of the present invention is to improve the construction ofcutter heads, more especially those equipped with a plurality of bladesor knives for twisting and beating or rabbeting, and analogous cuttingoperations, and to enable a thin blade of high speed steel to besecurely and adjustably mounted on a cutter head and firmly supportedthereon, whereby a blade or knife of the desired thinness may be safelyemployed.

Another object of the invention is to provide clamping means, adapted toengage a knife or blade with equal pressure at the inner and outerportions thereof, and capable of securely holding the same, especiallywhen the'blade becomes worn and it is necessary to advance or move thesame outwardly from its original position to maintain the properexternal gage.

With these and other objects in view, the invention consists in theconstruction and novel combination of parts hereinafter fully described,illustrated in the accompanying drawings, and pointed out in the claimshereto appended; it being understood that various changes in the form,proportion, size and minor details of construction, within the scope ofthe claims, may be resorted to without departing from the spiritorsacrificing any of the advantages of the invention.

In the drawings :Figure 1 is a perspective view of a cutter head,constructed in accordance with this invention and equipped with spiraland irregular blades. Fig. 2 is a transverse sectional view of the same.Fig. 3 is an end view of one of the spiral clamping bars. Fig. 4 is afront view of the same. Fig. 5 is an edge view of one of the spiralblades or knives. Fig. 6 is an end view of the same. Fig. 7 is asectional view of a circular cutter head, provided with straight knivesor blades. Fig. 8 is an elevation of the same.

Like numerals of reference designate corresponding parts in all thefigures of the drawings.

In the embodiment of the invention illustrated in Figs. 1 to 6inclusive, 1 designates a cutter head, provided with a pair of flat orstraight side faces 2 and having opposite curved faces 3, and designedto be either cast integral with the shaft 4 or bored centrally andmounted on the same in the ordinary manner. The cutter head may be ofany desired size, and it is provided in its straight flat faces 2 withlongitudinal undercut slots 5, in which slide heads 6 of bolts 7 forsecuring irregular cutters 8 to the fiat or straight faces of the cutterhead. The cutters 8 may be either irregular, as shown, or straight, asthe cutter head may be employed for smoothing and beating or rabbeting,and analogous operations. The knives or blades 8 are providedwit-h slots9 to receive the bolts 7, which are provided at their outer threadedportions with nuts 10, washers 11 being interposed between the nuts andthe blades. The bolts 7 and the slots 9 of the blades 8 permit an inwardand outward adjustment of the latter in the usual manner.

In order to enable cutter heads to be economically and safely equippedwith thin blades 12 of high speed steel, which cost from fifty toeight-y or ninety cents a pound, the cutter head is provided in each ofits curved faces with longitudinal grooves 13 for the reception of theknife or blade 12 and a clamping bar 14. The blade 12,which is seatedagainst one of the side walls of the groove 13, has a slight spiraltwist in order to operate in cutting with a shearing action to produce aclean out without chipping the material. The wall 15, which receives andforms a seat or abutment for the spiral blade 12, is spirally disposedto conform to the configuration of and to fit against the bladethroughout the entire length of the same. The blade is firmly heldagainst the wall 15 by the clamping bar 14, having a spiral side face 16to fit the spiral face of the blade, and provided at the opposite sideface with inner and outer inclined or angularly disposed portions 17 and18, which coact with inner and outer inclined or angularly disposedportions 19 and 20 of the side wall 21 of the groove. The inner andouter angularly disposed faces or portions 19 and 20 are inclined to theplane of the blade and the opposite side wall against which the blade isfitted, and they are also separated by a straight intermediate portionor face, arranged in substantial para-L lelism with the blade and theside wall against which the blade is fitted. The side wall 21 of thegroove is also of spiral formation to conform to the twist of the blade,and the inner and outer portions of the clamping bar are made taperingor wedgeshaped to form the angularly disposed or inclined faces 19 and20. The clamping bar is thereby enabled to produce a double wedgingaction in clamping the blade or knife, and it has been found by practicethat the blade or knife may be held more securely by this doubleclamping action than with a. single outer tapered portion, whichfrequently permits the blade to slip. The double wedging or clampingaction is particularly advantageous as the knife becomes worn and ismoved outwardly, the inner portion of the clamping bar tending to forceitself back of the inner edge of the blade and constituting more or lessof a stop for the same.

The clamping bar is provided at intervals with openings 22, arranged insubstantial parallelism with the plane of the blade and the adjacentport-ions of the side faces of the clamping bar and receiving adjustingscrews 23, having outer squared portions or heads 24, and provided withinner threaded portions, which engage threaded openings or sockets 25,formed in the cutter head, as clearly illustrated in Fig. 2 of thedrawings. The openings of the clamping bar are counter-bored at theirouter portions to provide shoulders 26, which are engaged by flanges 27of the adjusting screw. The shoulder 26 is located between the inner andouter inclined or angularly disposed faces of the cutter head and theclamping bar or member, and pressure is applied to the latter betweenthe spaced inner and outer wedging portions. The flanges 27 and thesquared portions 24 constitute the head of the screw, and the outerenlarged portion of the opening receives the flange 27 and. the squaredportion 24, which is adapted to be engaged by a suitable wrench. Theinner portion of the opening 22 is of slightly greater diameter than thescrew to permit the double wedging action of the clamping bar, which issecurely held against displacement by the adjusting screw. The inner andouter wedge-shaped portions produce an equal clamping of the blade attheinner and outer portions thereof, and the blade is effectually preventedfrom slipping. As the blade is firmly supported in the cutter head atboth sides, it may be constructed as thin as desired. The outer face 28of the clamping bar is recessed to provide-a suflioient space for thechip cut by the spiral blade. The spiral blade projects a uniformdistance throughout its entire length from the curved or arcuate face 3of the cutter, and it is angularly disposed with relation to the same toproduce the said shearing action. The curved faces 3 are true arcs,having for their centers the center of the cutter head.

In Figs. 7 and 8 of the drawings is illustrated a circular cutter head29, which, although narrower in the illustration, may be of any desiredlength, as will be readily understood. The circular cutter head isprovided with a plurality of straight knives or blades 30, but it may beequipped with spiral blades if desired. The straight blades or knives,which are designed to be constructed of thin high speed steel, or othersuitable material, are clamped in grooves 31 by clamping bars 32,secured in their adjustment by screws 33. The grooves, which are formedin the cutter head, are provided at one side with a straight wall 34, toform a central abutment for a straight blade 30, and the opposite wallof the groove is provided with inner and outer inclined or angularlydisposed portions 35 and 36, spaced apart and engaged by inclined orangularly disposed portions 37 and 38 of the adjacent side face of theclamping bar. The other side face of the clamping bar is straight to fitthe knife. The screw 33 engages threaded sockets or openings 39 of thecutter head, and it is provided with a squared outer end or portion, andhas a flange 40 to engage a shoulder 41, formed by counter-boring orenlarging the outer portion of the screw-receiving opening 42 of theclamping bar or member. The clamping bar or member is wedge-shaped atits inner and outer portions to form the inclined or angularly relatedfaces 37 and 38, and its inner and outer portions, through theadjustment of the screw 33, are forced laterally against the blade orknife 30 with equal pressure, whereby the knife or blade is efiectuallyprevented from slipping or working inwardly. Sufiicient space isprovided between the screw and the walls of the opening 42 .to permitthis action of the clamping bar or member. It will then be clear thatthe clamping means-employed for securing the blade in the groove of thecutter head may be employed with equal advantage for either straight orspirally arranged blades. In each instance the inner edge or face of theclamping bar or member is arranged in spaced relation with the bottom ofthe groove to permit the necessary inward movement of the clampingmember.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent, is

l. The combination of a cutter head provided with a groove having spacedinner and outer inclined or angularly related faces at one side wall ofthe groove and provided with a blade receiving face at the opposite sidewall of the groove, a blade arranged within the groove and fittedagainst the said blade receiving face, a clamping member arranged in thegroove and having one of its faces conforming to the configuration ofand fitted against the blade, its other side face being provided withinner and outer spaced inclined or angularly disposed portions engagingthe inclined or angularly disposed faces of the cutter head and adaptedto produce a clamping action on both the inner and outer portions of theblade and to cause the inner portion of the clamping member to tend toforce itself back of the inner edge of the blade and constitute more orless of a stop for the same as the blade becomes worn and is adjustedoutwardly, and a screw for forcing the clamping member inwardly over thesaid inclined or angularly disposed faces to aroduce a wedging action inclamping the bla e.

2. The combination of a cutter head provided with a groove and havinginner and outer inclined or angularly related faces at one side wall ofthe groove, the opposite side wall of the groove having a continuousblade receiving face, a blade fitted against the wall having the bladereceiving face, a clamping member arranged in the groove and havin innerand outer tapered or wedge-shape portions presenting inclined orangularly related faces to the inclined or angularly related faces ofthe cutter head and arranged to produce a clamping action at both theinner and outer portions of the blade and to cause the inner portion ofthe clamping member to tend to force itself back of the inner edge ofthe blade and thereby constitute more or less of a stop for the same asthe blade becomes worn and is adjusted outwardly, said clamping memberbeing also provided with an opening in substantial parallelism with theplane of the blade and having an enlarged outer portion forming anintermediate shoulder located at a point between the said inner andouter inclined or angularly disposed faces, and a screw extendingthrough the said opening and engaging the cutter head and provided witha head engaging the shoulder of the clamping member to produce apressure thereon at a point between the inner and outer inclined orangularly disposed faces, said screw being also of less diameter thanthe inner portion of the said opening to permit a lateral or wedgingaction of the clamping member.

In testimony, that I claim the foregoing as my own, I have heretoaffixed my slgnature in the presence of two witnesses.

CALVIN D. MARSH.

Witnesses:

J. H. ARNOLD, P. E. STRYKER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G.

